Green, Efficient Detection and Removal of Hg<sup<2+</sup< by Water-Soluble Fluorescent Pillar[5]arene Supramolecular Self-Assembly

Developing a water-soluble supramolecular system for the detection and removal of Hg<sup<2+</sup< is extremely needed but remains challenging. Herein, we reported the facile construction of a fluorescent supramolecular system (<b<H</b<<b<⊃</b<<b<G</b<)...
Ausführliche Beschreibung

Developing a water-soluble supramolecular system for the detection and removal of Hg<sup<2+</sup< is extremely needed but remains challenging. Herein, we reported the facile construction of a fluorescent supramolecular system (<b<H</b<<b<⊃</b<<b<G</b<) in 100% water through the self-assembly of carboxylatopillar[5]arene sodium salts (<b<H</b<) and diketopyrrolopyrrole-bridged bis(quaternary ammonium) guest (<b<G</b<) by host–guest interaction. With the addition of Hg<sup<2+</sup<, the fluorescence of <b<H</b<<b<⊃</b<<b<G</b< could be efficiently quenched. Since Hg<sup<2+</sup< showed synergistic interactions (coordination and Hg<sup<2+</sup<- cavity interactions with <b<G</b< and <b<H</b<, respectively), crosslinked networks of <b<H</b<<b<⊃</b<<b<G</b<Hg<sup<2+</sup< were formed. A sensitive response to Hg<sup<2+</sup< with excellent selectivity and a low limit of detection (LOD) of 7.17 × 10<sup<−7</sup< M was obtained. Significantly, the quenching fluorescence of <b<H</b<<b<⊃</b<<b<G</b<@Hg<sup<2+</sup< can be recovered after a simple treatment with Na<sub<2</sub<S. The reusability of <b<H</b<<b<⊃</b<<b<G</b< for the detection of Hg<sup<2+</sup< ions was retained for four cycles, indicating the <b<H</b<<b<⊃</b<<b<G</b< could be efficiently used in a reversible manner. In addition, the <b<H</b<<b<⊃</b<<b<G</b< could efficiently detect Hg<sup<2+</sup< concentration in real samples (tap water and lake water). The developed supramolecular system in 100% water provides great potential in the treatment of Hg<sup<2+</sup< detection and removal for environmental sustainability. Ausführliche Beschreibung